Double set hydraulic anchor



Feb. 28, 1967 M. P. LEBOURG DOUBLE SET HYDRAULIC ANCHOR 2 Sheets-Sheet 1Filed June 11, 1964 Mawvre [960 0/9 IN V EN TOR.

ZMXQM ATTOR/Vf) Feb. 28, 1967 M. P. LEBOURG DOUBLE SET HYDRAULIC ANCHOR2 Sheets-Sheet 2 Filed June 11, 1964 May/v06 P. leau/y INVENTOR.

3,306,361 DGUBLE SET HYDRAULIC ANCHOR Maurice P. Lebourg, Houston, Tex.,assignor, by mesne assignments, to Schiumherger Technology Corporation,Houston, Tex.. a corporation of Texas Filed June 11, 1964, Ser. No.374,430 13 Claims. (Cl. 166-122) This invention relates to apparatusadapted for anchoring a well tool in place within a well bore; and, moreparticularly, to hydraulically actuated anchors which, when set inplace, will be secured against hydraulic pressures in the well actingfrom either direction by an anchoring force proportionately related tothe acting pressure.

In conducting such well-completion operations as acidizing, cementing,or fracturing, a full-opening well packer dependently coupled from atubing string is positioned at a particular depth in a cased well andthe packer set to isolate the formation interval to be treated from theremainder of the well bore thereabove. Treating fluids are then pumpeddownwardly at high pressure through the tubing and full-bore packer andintroduced into the formation being treated through perforationsappropriately located in the casing.

It will be appreciated that such full-bore packers must be capable ofwithstanding high pressures acting from either direction. Furthermore,during the course of typical completion operations, the packer can besubjected to high pressures acting alternately from both and above andbelow the packer. Accordingly, it is necessary to securely anchor thepacker against movement in either longitudinal direction.

Heretofore, extendible slip members have typically been employed toanchor such packers against movement in at least one direction.Extendible anchoring members have also been developed which arehydraulically actuated by the fiuid being pumped through the tubing andsecure the apparatus against shifting.

Accordingly, it is an object of the present invention to provide new andimproved anchoring apparatus for well packers, which apparatus hashydraulically actuated wallengaging members which are pressed intoanchoring engagement with a force proportionately related to thepressure of fluids in the well.

It is an additional object of the present invention to provide new andimproved well tool anchors which will anchor the tools in response to apressure differential acting from either direction.

Anchoring apparatus arranged in accordance with the present inventionincludes a selectively operable hydraulic system responsive to fluidpressure in a well and adapted to maintain wall-engaging means inanchoring engagement with a force proportionately related to a fluidpressure differential across the apparatus.

The novel features of the present invention are set forth withparticularity in the appended claims. The present invention, both as toits organization and manner of operation together with further objectsand advantages thereof, may best be understood by way of illustrationand example of certain embodiments when taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a view of a full-bore packer having an anchor thereonemploying principles of the present invention and depicted as they wouldappear within a well bore;

FIG. 2 is a detailed cross-sectional View of an embodiment of an anchor;

FIG. 3 is a cross-sectional view taken along .the line 33 of FIG. 2;

FIG. 4 is a schematic representation of a portion of the anchor shown inFIG. 2; and

FIG. Sis a view of an alternate embodiment of an anchor.

nited States Patent Fice As seen in FIG. 1, a typical full-bore packer10 is dependently connected in a tubing string 11 and positioned withina well bore 12 having a casing 13 set therein. An anchor 14incorporating principles of the present invention is serially coupledbetween the upper end of the tubular body member or mandrel 15 of thefull-bore packer 10 and the lower end of a conventionally arrangedbypass valve 16, which is in turn connected to the lower end of thetubing string 11. As is conventional in the art, such a bypass valve 16is opened whenever the fullbore packer 111 is being shifted Within afluid-filled well to divert some of the fluids through the central bore17 ofv the mandrel 15 and bypass valve before returning to the annulusof the well bore 12. Whenever the packer 10 has been set in position,the bypass valve 16 is of course closed to prevent fluid communicationthrough the mandrel bore 17 of the sealingly engaged packer 10.

The typical full-bore packer 10 illustrated in FIG. 1 includes arotatable tubular body member or mandrel 15 slidably disposed within andextended through a tubular housing member 18. Elastomeric packing means19 are mounted around the upper portion of the housing 18 intermediatean outwardly directed shoulder on the mandrel 15 and a slidably disposedslip bowl 20. Normally retracted slip members 21 are operatively mountedaround the upper end of the housing 18 and cooperatively engaged withthe slip bowl 20 in the well-known manner. Conventional drag blocks 22are provided to secure the housing 18 to the casing 13 as the mandrel 15is manipulated relative to the housing to extend the packing means 19and slips 21 against the casing. Conventionally arranged I-slots andJ-pins (not shown) selectively latch the mandrel 15 relative to thehousing 18 to keep the packer 10 retracted.

Accordingly, when the packer 10 is to be set, the tubing string 11 ispicked up slightly and then manipulated in a particular manner to freethe mandrel 15 for downward travel. As the mandrel 15 is lowered, thedrag blocks 22 restrain the housing 18 as the downward movement of themandrel successively drives the slip bowl 20 downwardly to extend theslips 21 and foreshorten the packing means 19 in the well-known manner.By the time the mandrel 15 has reached its lower limit of travel, theslips 21 will be engaged against the casing 13 and the packing means 19displaced into sealing engagement there-' with. It will be appreciated,of course, that once set, the slips 21 will then prevent the full-borepacker 10 from moving further downwardly within the casing 13.

As seen in FIG. 1, the hydraulic anchor 14 is dependently coupled in thetubing string 11 to the upper end of the packer mandrel 15. Aself-contained hydraulic system therein is adapted to operativelyactuate the anchor 14 in response to a pressure differential across thepacking means 19. Thus, whenever the bypass valve 16 is closed after thepacking means 19 has been set, the anchor 14 will be anchoringly engagedto secure the mandrel 15 in its lower position as well as to prevent thepacker 10 from shifting upwardly.

Turning now to FIG. 2, the anchor 14 includes a tubular housing 23having a longitudinal bore 24 of a uniform diameter extendingtherethrough. This longitudinal bore 24 is of course in fluidcommunication at all times with the central bore 17 of the packermandrel 15. Mounted around the anchor housing 23 is an expansibleelastomeric sleeve 25 encircling the housing with a plurality ofelongated casing-engaging members 26, 27 being mounted uniformly aroundthe periphery of the sleeve. The enlarged upper 28 and lower 29 ends ofthe elastomeric sleeve 25 are sealingly secured within opposedperipheral recesses 31), 31 around the housing 23 to provide afluidtight space 32 between the sleeve and housing,

Each of the casing-engaging members 26, 27 is elongated and has a thick,arcuate, cross-section (FIG. 3). Alternate ones 26 of thesecasing-engaging members are centrally aligned and mounted along theouter convex surface of relatively thin, elongated, arcuate backingmembers 33. A sufficient number of these mounted members 26 are disposeduniformly around the periphery of the elastomeric sleeve 25 that thebacking members 33 substantially encompass the sleeve. The remainingunmounted casing-engaging members 27 are alternately disposed betweenthe mounted casing-engaging members 26 in such a manner that theunmounted members 27 straddle adjacent backing members 33 and cover thegap 34 therebetween.

The ends of the casing-engaging members 26, 27 are beveled, as at 35(FIG. 2), for reception within the opposed annular housing recesses 30,31. Springs 36, 37 operatively engaged at opposite ends of the members26, 27 bias the members inwardly. It will be appreciated, therefore,that although the casing-engaging members 26, 27 will be moved radiallyoutwardly against springs 36, 37 whenever the elastomeric sleeve 25 isinflated, the beveled ends of the members cannot escape from the housingrecesses 30, 31.

Turning now to the hydraulic system of the anchor 14, the housing 23 isformed in such a manner as to provide a first annular chamber 38 of aparticular cross-sectional area in the housing and a second annularchamber 39 of a smaller cross-sectional area immediately thereabove andin coaxial alignment therewith. Radial ports 40 at the junction of theannular chambers 38, 39 provide fluid communication therefrom to theinner bore 24 of the anchor 23. A second group of ports 41 is providedto establish fluid communication from outside of the housing 23 into thelower portion of the lower annular chamber 38. A fluid passage 42 withinthe housing 23 extending from the upper portion of the upper annularcham ber 39 is divided into separate branches 43, 44 (FIG. 4), each ofwhich lead into a valve chamber 45 thereabove. A second fluid passage 46leads from the valve chamber 45 to the fluid-tight space 32 beneath theelastomeric sleeve 25.

A complementarily formed annular piston member 47 is slidably disposedwithin the lower annular chamber 38 and fluidly sealed therein withrespect to the housing 23 by O-rings 48, 49. An elongated tubular pistonmember 50 is complementarily fitted and slidably disposed within theupper annular chamber 39 and fluidly sealed therein relative to thehousing 23 by O-rings 51, 52. A compression spring 53 within the upperpiston chamber 39 is engaged between a downwardly directed housingshoulder 54 and the upper face 55 of the tubular piston member 50. Thisspring 53 biases the tubular piston member 50 downwardly so that itslower face 56 will normally rest upon the upper face 57 of the annularpiston member 47 and urge that piston downwardly as well until its lowerface 58 comes to rest on the bottom of chamber 38.

It will be appreciated that when the upper piston chamber 39, valvechamber 45, fluid passages 42-44, 46 and the fluid-tight space 32 arefilled with a suitable hydraulic fluid, a hydraulic pressure will bedeveloped within this system whenever the tubular piston member 50 isadvanced further upwardly into the upper piston chamber 39 as. shown inFIG. 2. Furthermore, whenever a hydraulic pressure is so developed, theelastomeric sleeve 25 will be inflated and press the casing-engagingmembers 26, 27 against the casing.

Whenever the packer and its cooperatively arranged anchor 14 arepositioned in a fluid-filled well bore and the packing means 19 set, thepressure of the fluids above the packing means will be transmittedthrough the outer fluid ports 41 through the anchor housing 23 againstthe lower face 58 of the annular piston member 47 as well as act on theoutside of the elastomeric sleeve 25. The

pressure from below the packing means 19 will be transmitted through theopen mandrel bore 17 into the inner bore 24 of the anchor 14 and bedirected through inner ports 49 simultaneously against the upper face 57of the annular piston member 47 and the lower face 56 of the tubularpiston member 50. Thus, it will be appreciated that the piston members47, will shift within their respective chambers 38, 39 in response to apressure differential across the engaged packing means 19.

To illustrate the operation of the anchor 14 and its hydraulic system,assume first that the pressure of the fluids in the well below the setpacking means 19 is greater than the pressure of the fluids thereabove.In this instance, the pressure that is communicated through the mandrelbore 17 to within the inner bore 24 of the anchor 14 will be greaterthan that outside of the anchor. The annular piston member 47 will bedriven downwardly since the pressure acting on its upper face 57 isgreater than that acting on its lower face 58. This greater pressureacting on the lower face 56 of the tubular piston member 50 of courseadvances the piston further upwardly into the upper piston chamber 39 todisplace fluid upwardly and develop a hydraulic pressure within thefluid-filled hydraulic system. The pressure so developed will of coursebe substantially equal to the greater pressure within the anchors innerbore 24. Since the hydraulic pressure inside of the sleeve 25 is greaterthan the pressure of the fluids in the well bore outside of theelastomeric sleeve, the sleeve will be inflated. It will be appreciated,therefore, that the wall-engaging members 26, 27 will be pressed againstthe casing with a force proportionately related to the pressuredifferential across the set packing means 19 of the fluids in the well.

Should, however, the conditions within the well be reversed and thepressure of the fluids in the well above the packing means 19 instead begreater than that of those below, this higher fluid pressure will actthrough the outer ports 41 to shift the annular piston member 47upwardly. Since the lower face 56 of the tubular piston member 50normally rests on the annular piston 47, as the annular piston member 47is shifted upwardly, the tubular piston is advanced upwardly to developpressure within the fluid-filled hydraulic system. The pressure sodeveloped, however, will be proportionately greater than the pressure ofthe fluids in the well bore above the packing means 19 as determined bythe ratio of the effective cross-sectional area of the annular pistonmember 47 divided by the effective cross-sectional area of the tubularpiston member 50. It is, of course, necessary in this instance that thedeveloped hydraulic pressure be greater than the pressure of the fluidsabove the packing means 19 inasmuch as this latter pressure is not onlythe actuating pressure but is also being applied against the outside ofthe elastomeric sleeve 25. Thus, the casing-engaging members 26, 27 willagain be pressed against the casing with a force proportionately relatedto the pressure differential across the set packing means 19 of thefluids in the well.

In either of the two above-described conditions, it will be realizedthat the casing-engaging members 26, 27 will remain engaged with thecasing only so long as the packing means 19 is set to maintain apressure differential on opposite sides thereof. Thus, whenever thepacking means 19 is released, the pressure differential will no longerexist and the anchor 14 will automatically retract as the spring 53returns the tubular piston member 50 to its initial position as thesleeve 25 deflates.

Whenever the retracted full-bore packer 10 is being moved through afluid-filled well bore, it is not at all unusual for the restriction topassage of fluids around the packer to create a slight pressuredifferential between the outside of the packer and its mandrel bore 17.For example, as the package 10 is being pulled upwardly, the fluidpressure outside of the anchor 14 above the packing means 19 will besomewhat greater than that below the packing means and in the mandrelbore 17. This pressure differential could of course become sufficientlygreat that both piston members 47, 50 would shift upwardly and extendthe casing-engaging members 26, 27 against the casing to retard, if notprevent, the packer from moving further.

Accordingly, to prevent premature actuation of the anchor 14, aconventional spring-loaded, normally-closed, check valve 59 (FIGS. 2Aand 4) is connected in series between the upper piston chamber 39 andthe fluid-tight space 32 beneath the elastomeric sleeve 25. The valve 59is disposed in the valve chamber 45 with its inlet connected to one 43of the branch portions of the lower fluid passage 42 and its outlet opento the valve chamber. This valve 59 is biased to remain closed until thepressure in the upper piston chamber 39 exceeds that in the fluidtightspace 32 by a predetermined differential. Thus, the elastomeric sleeve25 will not be inflated until a substantial hydraulic pressure isdeveloped in the upper piston chamber 39.

The other conventional check valve 60 (behind valve 59 in FIG. 2)disposed within the valve chamber 45 has its inlet open to the valvechamber and its outlet connected to the other branch portion 44 of thelower fluid passage 42. Although it is in parallel with the springloadedvalve 59, this check valve 60 operates in the opposite direction andopens only when the pressure in the valve chamber 45 exceeds that in thelower fluid passage 42. Thus, this valve 60 opens only to allowhydraulic fluid to return to the upper piston chamber 39 as theelastomeric sleeve 25 contracts and the tubular piston member 50 returnsto its normal position.

Thus, whenever the tubular piston 50 inadvertently shifts upwardly inresponse to a pressure differential across the packing means 19 as theretracted packer 10 is moved through a well bore, the hydraulicpresssure so developed is insufilcient to overcome the bias holding thespring-loaded valve 59 closed. The other valve 60 of course remainsclosed as well.

When the packing means 19 is set, the hydraulic pressure developed inthe upper piston chamber 39 must of course be suflicient to overcome thebias and open the valve 59 before hydraulic pressure can buildup in theremainder of the system. When, however, the springloaded valve 59 doesopen, the pressure in the valve chamber 45 will of course be lower thanthat in the upper piston chamber 39 by an amount proportionate to thebias on the valve. Thus, the pressure diflerential will hold the othercheck valve 60 closed so long as the tubular piston 50 is being urgedupwardly into the upper piston chamber 39. This other check valve 60will of course open whenever the hydraulic pressure within the upperpiston chamber 39 drops below that in the valve chamber 45. Thus,whenever the packing means 19 is released and the pressure of the fluidsin the well is equalized across the packing means, the elastomericsleeve 25 will contract and displace hydraulic fluids downwardly throughthe opened check valve 60 and back into the upper piston chamber 39 asthe spring 53 returns the tubular piston 50 to its normal position.

Turning now to FIG. 5, the anchor 100 includes a tubular housing 101having a central axial bore 102 of uniform diameter extendingtherethrough. At a central portion of the housing 101 a plurality ofoutwardly facing piston members 103 are operatively mounted withinradial bores 104 and fluidly sealed therein by O-rings 105. Leaf springs106 fastened to the housing 101 are arranged to retain the pistonmembers 103 and to bias the piston members inwardly whenever they areextended. The outer face of each piston member 103 is serrated toprovide casing-engaging teeth or wickers 107.

The inner end of each of the radial bores 104 opens to a fluid-tightspace 108 which extends above and below the casing-engaging pistonmembers 103. At the open upper end of this fluid-tight space 108, anannular cham- 0 her 109 is formed in the housing 101. Similarly, at theopen lower end of the fluid-tight space 108, a second annular chamber110 is formed in the housing 101.

The upper annular chamber 109 is formed into an enlarged upper portion111 and a lower portion 112 of a smaller cross-sectional area. Anannular piston member 113 having an enlarged upper portion 114 and areduced diameter lower portion 115 is complementarily formed andslidably disposed within the upper annular chamber 109 and fluidlysealed therein by O-rings 115- 118. An outer port 119 through thehousing 101 provides fluid communication from the exterior of the anchorto the upper face 120 of the enlarged piston portion 114. An inner port121 provides fluid communication from the inner bore 102 of the housing101 to the lower face 122 of the enlarged portion 114 of the annularpiston member 113. A compression spring 123 is disposed between thelower end 124 of the piston member 113 and an upwardly directed housingshoulder 125.

A complementarily formed annular piston member 126 is slidably disposedwithin the lower annular chamber and fluidly sealed therein by O-rings127, 128 mounted around its outer and inner surfaces. An inner port 129provides fluid communication from the inner bore 102 of the housing 101to the lower face 130 of the annular piston member 126.

Thus, it will be appreciated that with the upper annular chamber 109,the lower annular chamber 110, the fluidtight space 108 and that portionof the bores 104 beneath the casing-engaging piston members 103 beingfilled with a suitable hydraulic fluid, a hydraulic pressure will bedeveloped Within the system whenever either piston member 113, 126 isadvanced toward the casing-engaging members 103. It is to beunderstoood, of course, that whenever such a hydraulic pressure is sodeveloped, the casingengaging piston members 103 will be forcedoutwardly to press the casing-engaging teeth 107 against the casing.

To illustrate the operation of the anchor 100 and its hydraulic system,assume first that the pressure of the fluids in the well beneath the setpacking means therebelow is greater than the pressure of the fluidsthereabove. Thus, the greater pressure transmitted through the centralbore 17 of the packer body member or mandrel 15 to within the inner bore102 of the anchor 100 will act through the inner port 121 to drive theupper piston member 113 upwardly until its upper face engages adownwardly directed housing shoulder 131. At the same time, however,this greater pressure is acting through the inner port 129 on the lowerface of the lower piston member 126 to drive this piston upwardly todevelop a hydraulic pressure within the fluid-filled hydraulic system.This pressure so developed will of course be equal to the fluid pressurewithin the inner bore 102 of the anchor. This developed hydraulicpressure is, however, greater than the pressure of the fluids above thepacking means outside of the piston members 103 so that thecasingengaging members will be driven outwardly and pressed against thecasing with a force proportionately related to the pressure diflerentialacross the set packing means.

Where the conditions within the well are reversed and the pressure ofthe fluids above the set packing means is greater than that therebelow,the higher pressure is now outside of the anchor 100 and will actthrough outer port 119 to drive the upper piston member 113 downwardly.As this piston member 113 is driven downwardly, it will also develop apressure within the fluid-filled hydraulic system. This developedpressure, however, will be proportionately greater than the pressure ofthe fluids in the well above the packing means as determined by theratio of the eifective cross-sectional area of the enlarged portion 114divided by that of the reduced portion 115 of the upper piston member113. It is necessary, of course, that this developed hydraulic pressurebe greater than that of the fluids above the packing means since thislatter pressure is simultaneously imposed against the outer faces 107 ofthe casing-engaging members 103. Thus, by developing this greaterhydraulic pressure, the casing-engaging piston members 103 will again bepressed outwardly into engagement against the casing with a forceproportionately related to the pressure differential across the setpacking means.

It will be understood, of course, that whenever the anchor 19% and thefull-bore packer are being shifted in either direction through thefluid-filled well bore, the leaf springs 106 can be made sufficientlystrong to prevent the casing-engaging piston member 103 frominadvertently extending. Furthermore, it will be appreciated that as theanchor 100 is being pulled upwardly through a fluidfilled well bore, anytendency of well fluids acting through the outer port 119 to shift theupper piston 113 and develop a slight hydraulic pressure will beresisted by the compression spring 123.

It will be realized that either the anchor 14 or anchor 100 will beeffective as an anchor for well tools in other situations so long as afluid pressure differential exists. For example, by placing a choke inthe central bore of either of the anchors 14, 106 the passage of fluidsthrough the bore would create a pressure differential which could beutilized for acutating the anchor.

Thus, it will be appreciated that the present invention provides new andimproved anchors for securing well tools within a well bore. Theseanchors will be effective to prevent a well tool from being shiftedWithin a well bore by extreme pressure differentials acting against itfrom either direction. applied by the new and improved anchors will beproportionately related to the pressure differential acting on the tool.

While particular embodiments of the present invention have been shownand described, it is apparent that changes and modifications may be madewithout departing from this invention in its broader aspects and,therefore, the aim in the appended claims is to cover all such changesand modifications as fall Within the true spirit and scope of thisinvention.

What is claimed is:

1. A well packer sized and adapted for reception in a well boreincluding: means for packing-off a well bore; anchoring means on saidwell packer including extendible fluid-actuated wall-engaging means forengaging the wall of a well bore; and hydraulic means selectivelyresponsive to a fluid pressure differential in a well bore either aboveor below said packing-off means for developing an actuating pressure toextend and press said wall-engaging means into anchoring engagement witha force proportionate to this pressure differential to anchor said wellpacker.

2. A well packer sized and adapted for reception in a well boreincluding: means for packing-off a well bore; means responsive tohydraulic pressure for anchoring said well packer relative to the wallof a well bore; and means for applying hydraulic pressure to saidanchoring means in response to a pressure differential acting fromeither above or below said packing-off means for anchoring said wellpacker to the well bore with a force dependent upon said differentialpressure across said packing-off means.

3. In a well packer sized and adapted for reception in a well bore: atubular housing; packing means operatively mounted on said housing andadapted for expansion into sealing engagement with a well bore; meansfor selectively expanding said packing means including a body memberoperatively arranged within said housing; anchoring means adapted tosecure said packer against longitudinal movement relative to the wellbore whenever said packing means is sealingly engaged includingoutwardly-extendible wall-engaging means on said body member responsiveto hydraulic pressure to press said wall-engaging means into anchoringengagement with the Well bore; and hydraulic means responsive to apressure differential acting from either above or below said packingmeans for applying a hydraulic pressure to press said wall-engagingmeans into Furthermore, the anchoring forces 0 anchoring engagement witha force proportionate to this pressure differential.

4. In a well packer sized and adapted for reception in a well bore; atubular housing; packing means operatively mounted on said housing andadapted for expansion into sealing engagement with a Well bore; meansfor selectively expanding said packing means including a body memberhaving a radial bore and being operatively arranged Within said housing;anchoring means adapted to secure said packer against longitudinalmovement relative to the well bore whenever said packing means issealingly engaged including a piston member slidably disposed in saidradial bore and fluidly sealed therein to provide a fluidtight spacetherein, said piston member being adapted to move outwardly, uponapplication of hydraulic pressure in said fluid-tight space, intoanchoring engagement with the well bore; and hydraulic means responsiveto a pressure differential acting from either above or below saidpacking means for applying a hydraulic pressure in said fluid-tightspace to press said piston member into anchoring engagement with a forceproportionate to this pressure differential.

5. In a well packer sized and adapted for reception in a well bore: atubular housing; packing means operatively mounted on said housing andadapted for expansion into sealing engagement with a well bore; meansfor selectively expanding said packing means including a body memberoperatively arranged within said housing; anchoring means adapted tosecure said packer against longitudinal movement relative to the wellbore Whenever said packing means is sealingly engaged including aninflatable sleeve sealingly mounted around said body member to provide afluid-tight space therebetween and wall-engaging means mounted aroundsaid sleeve, said sleeve being adapted to inflate, upon application ofhydraulic pressure in said fluidtight space, to press said wall-engagingmeans into anchoring engagement with the well bore; and hydraulic meansresponsive to a pressure differential acting from either above or belowsaid packing means for applying a hydraulic pressure in said fluid-tightspace to press said Wall-engaging means into anchoring engagement with aforce proportionate to this pressure differential.

6. The packer of claim 5 wherein said wall-engaging means comprise: aplurality of elongated and arcuate rigid backing memberscircumferentially spaced around said sleeve to substantially enclose itexcept at gaps between adjacent longitudinal edges of said backingmembers; first elongated wall-engaging members mounted on each of saidbacking members and extending longitudinally thereon substantially thefull length of said backing members; second elongated wall-engagingmembers disposed between adjacent ones of said first wall-engagingmembers and extending substantially the full length of said backingmembers to cover said gaps; and abutment means on said body member ateach end of said wallengaging members for limiting them to substantiallylateral movement; and piston means between said sleeve and each of saidabutment means and movable longitudinally toward the ends of saidwall-engaging members in response to said hydraulic pressure forcovering the portions of said sleeve between said ends and said abutmentmeans.

7. In a well packer sized and adapted for reception in a well bore: atubular housing; packing means operatively mounted on said housing andadapted for expansion into sealing engagement with a well bore; meansfor selectively expanding said packing means including a body memberhaving a chamber therein and being operatively arranged within saidhousing; anchoring means adapted to secure said packer againstlongitudinal movement relative to the well bore whenever said packingmeans is sealingly engaged including outwardly-extendible wall-engagin gmeans mounted on said body member and fluidly sealed relative thereto toprovide a fluid-tight space therebetween, said wall-engaging means beingadapted to extend, upon application of hydraulic pressure in saidfluid-tight space, into anchoring engagement with the well bore; andhydraulic means responsive to a pressure differential across saidpacking means for applying a hydraulic pressure in said fluid-tightspace to press said wall-engaging means into anchoring engagement with aforce proportionately related to this pressure differential including apistonmember slidably disposed within said chamber and adapted to shifttherein in response to this pressure differential; means fluidly sealingsaid piston member within said chamber for fluidly isolating a portionof said chamber; and passage means providing fluid communication betweensaid isolated chamber portion and said fluid-tight space, all beingfilled with a hydraulic fluid.

8. In a well packer sized and adapted for reception in a well bore: atubular housing; packing means operatively mounted on said housing andadapted for expansion into sealing engagement with a well bore; meansfor selectively expanding said packing means including a body memberhaving a cylindrical chamber therein and being operatively arrangedwithin said housing; anchoring means adapted to secure said packeragainst longitudinal movement relative to the Well bore whenever saidpacking means is sealingly engaged including outwardly-extendiblewall-engaging means mounted on said body member and fluidly sealedrelative thereto to provide a fluid-tight space therebetween, saidwall-engaging means being adapted to extend, upon application ofhydraulic pressure in said fluid-tight space, into anchoring engagementwith the well bore; and hydraulic means responsive to a pressuredifferential acting from either above or below said packing means forapplying a hydraulic pressure in said fluid-tight space to press saidwall-engaging means into anchoring engagement with a forceproportionately related to this pressure differential including firstand second piston members slidably disposed within said chamber andadapted to shift therein in response to this pressure differential;first and second means respectively fluidly sealing said piston memberswithin said chamber for fluidly isolating separate portions of saidchamber; first passage means providing fluid communication from the wellbore at a point longitudinally displaced in one direction from saidpacking means to said chamber adjacent one end of said first pistonmember; second passage means providing fluid communication from the wellbore at a point longitudinally displaced in the other direction fromsaid packing means to said chamber adjacent one end of said secondpiston member; and third passage means providing fluid communicationfrom said chamber adjacent the other ends of said piston members to saidfluid-tight space, all being filled with a hydraulic fluid.

9. In a well packer sized and adapted for reception in a well bore: atubular housing; packing means operatively mounted on said housing andadapted for expansion into sealing engagement with a well bore; meansfor selectively expanding said packing means including a body memberhaving a cylindrical chamber therein and being operatively arrangedwithin said housing; anchoring means adapted to secure said packeragainst longitudinal movement relative to the well bore Whenever saidpacking means is sealingly engaged including outwardly-extendiblewall-engaging means mounted on said body member and fluidly sealedrelative thereto to provide a fluid-tight space therebetween, saidwall-engaging means being adapted to extend, upon application ofhydraulic pressure in said fluid-tight space, into anchoring engagementwith the well bore; and hydraulic means responsive to a pressuredifferential acting from either above or below said packing means forapplying a hydraulic pressure in said fluid-tight space to press saidwall-engaging means into anchoring engagement with a forceproportionately related to this pressure differential including firstand second piston members slidably disposed within said chamber andadapted to shift therein in response to this pressure differential, saidfirst piston member being adapted to engage and shift said second pistonmember whenever said first piston member shifts toward said secondpiston member; first and second means respectively fluidly sealing saidpiston members within said chamber for fluidly isolating separateportions of said chamber; first and second passage means respectivelyproviding fluid communication from the well bore at points separatedfrom one another by said packing means to said chamber on opposite sidesof said first piston member; and third passage means providing fluidcommunication from said chamber at a point adjacent the other end ofsaid second piston member to said fluid-tight space, all being filledwith a hydraulic fluid.

10. In a well packer sized and adapted for reception in a well bore: atubular housing; packing means operatively mounted on said housing andadapted for expansion into sealing engagement with a well bore; meansfor selectively expanding said packing means including a body memberhaving a cylindrical chamber with a first portion of a greatercross-sectional area than the remaining portion of said chamber, saidbody member being operatively arranged within said housing; anchoringmeans adapted to secure said packer against longitudinal movementrelative to the well bore whenever said packing means is sealinglyengaged including outwardly-extendible Wall-engaging means mounted onsaid body member and fluidly sealed relative thereto to provide afluid-tight space therebetween, said wall-engaging means being adaptedto extend, upon application of hydraulic pressure ir said fluidtightspace, into anchoring engagement with the well bore; and hydraulic meansresponsive to a pressure differential acting from either above or belowsaid packing means for applying a hydraulic pressure in said fluid-tightspace to press said wall-engaging means into anchoring engage ment witha force proportionately related to this pressure differential includinga first piston member slidably disposed in said first chamber portion; asecond piston member slidably disposed in said remaining chamberportion; said first piston member being adapted to engage and shift saidsecond piston whenever said first piston member shifts toward saidsecond piston member; first and second means respectively fluidlysealing said piston members relative to said chamber; first and secondpassage means respectively providing fluid communication from the wellbore at points separated from one another by said packing means to saidchamber on opposite sides of said first piston member; and third passagemeans providing fluid communication from said remaining chamber portionat a point separated from said first chamber portion by said secondpiston member to said fluid-tight space, said remaining chamber portion,fluid-tight space and third passage means being filled with a hydraulicfluid.

11. In a well packer sized and adapted for reception in a Well bore: atubular housing; packing means operatively mounted around said housingand adapted for expansion into sealing engagement with a well bore; slipmembers movably mounted on said housing adjacent one end of said packingmeans and operatively arranged and adapted for outward extension intoanchoring engagement with a well bore to secure said packer against1ongitudinal movement in one direction relative to the Well bore; meansfor selectively extending said slip members and expanding said packingmeans including a body member engaged with the other end of said packingmeans, said body member having a cylindrical chamber therein with afirst portion of a greater cross-sectional area than the remainingportion of said chamber, said body member being operatively arrangedwithin said packing means and extending into said housing; an inflatableelastomeric sleeve sealingly mounted around said body member to providea fluid-tight space therebetween at a point longitudinally displaced inone direction from said other end of said packing means; wall-engagingmeans operatively mounted around said elastomeric sleeve, saidelastomeric sleeve being adapted to inflate, upon application ofhydraulic pressure in said fluid-tight space, to press saidwall-engaging means into anchoring engagement with the well bore andsecure said packer against longitudinal movement in the oppositedirection; and hydraulic means responsive to a pressure differentialacting from either above or below said packing means for applyinghydraulic pressure in said fluid-tight space to press said wall-engagingmeans into anchoring engagement with a force proportionately related tothis pressure differential including; first and second slidable pistonmembers respectively disposed in said first and remaining chamberportions; said second piston member being adapted to be engaged by saidfirst piston member and shifted thereby whenever said first pistonmember shifts toward said second piston member; first and second meansrespectively fluidly sealing said piston members within said chamber;first passage means providing fluid communication between the well borefrom a point longitudinally displaced in said one direction from saidpacking means to said first chamber portion at a point separated fromsaid remaining chamber portion by said first piston member; secondpassage means providing fluid communication between the well bore from apoint longitudinally displaced in the opposite direction from saidpacking means to said chamber at a point intermediate said pistonmembers; and third passage means providing fluid communication from saidremaining chamber portion at a point separated from said first chamberportion by said second piston member into said fluid-tight space, saidremaining chamber portion, fluid-tight space and third passage meansbeing filled with a hydraulic fluid.

12. As a sub-combination, an anchor comprising: a housing; a resilientsleeve disposed around said housing and sealingly secured at each endthereof to said housing to provide an enclosed space between said sleeveand housing; a plurality of elongated and arcuate rigid backing memberscircumferentially spaced around said sleeve and having adjacentlongitudinal edges; first wall-engaging vide an enclosed space betweensaid sleeve and housing;

means on each end of said sleeve for fluidly sealing said sleeve ends tosaid housing and preventing outward distortion of said sleeve ends; aplurality of elongated and arcuate rigid backing members between saidend-sealing means and circumferentially spaced around said sleeve toJbstantially enclose said sleeve except at gaps between adjacentlongitudinal edges of said backing members; first.

elongated wall-engaging members mounted on each of said backing members;second elongated wall-engaging members disposed between adjacent ones ofsaid first wallengaging members and covering said gaps; and abutmentmeans on said housing at each end of said members for limiting saidmembers to substantially lateral movements.

References Cited by the Examiner UNITED STATES PATENTS 2,370,832 3/1945Baker 166-120 2,603,163 7/1952 Nixon 166212 2,881,841 4/1959 Page l662122,925,128 2/1960 Page 166121 2,970,651 2/1961 Roberts 166--212 3,008,52311/1961 Clark et al l66l34 X 3,211,227 10/1965 Mott 166l20 3,233,6752/1966 Tamplen et al. 166-420 CHARLES E. OCONNELL, Primary Examiner.

D. H. BROWN, Assistant Examiner.

2. A WELL PACKER SIZED AND ADAPTED FOR RECEPTION IN A WELL BOREINCLUDING: MEANS FOR PACKING-OFF A WELL BORE; MEANS RESPONSIVE TOHYDRAULIC PRESSURE FOR ANCHORING SAID WELL PACKER RELATIVE TO THE WALLOF A WELL BORE; AND MEANS FOR APPLYING HYDRAULIC PRESSURE TO SAIDANCHORING MEANS IN RESPONSE TO A PRESSURE DIFFERENTIAL ACTING FROMEITHER